System and method for controlling temperature of industrial processing devices

ABSTRACT

A system and method for controlling the temperature of industrial processing devices includes a central liquid supply having a supply section and a return section and at least one processing device temperature control subsystem in liquid transmission connection with the central liquid supply for generally maintaining the temperature and pressure of liquid being circulated around an industrial processing device at a designated liquid temperature set point which includes a variable-speed pump, control valve and control device which controls the temperature of the liquid in the subsystem by speeding up, slowing down or shutting off the pump to ensure that the subsystem liquid temperature remains approximately equal to the designated liquid temperature set point as determined by the processing device associated with the subsystem and opens or closes the control valve to add or release liquid from the subsystem to maintain the desired pressure within the system.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates generally to systems and methods forcooling industrial processing devices and, more particularly, to asystem and method for controlling the temperature of industrialprocessing devices which includes a central liquid supply having asupply-section and a return section and at least one processing devicetemperature control subsystem for generally maintaining the temperatureof liquid being circulated around an industrial processing device at adesignated liquid temperature set point which includes a variable-speedpump, control valve and control device which controls the temperature ofthe liquid in the subsystem by speeding up, slowing down or shutting offthe pump to ensure that the subsystem liquid temperature remainsapproximately equal to the designated liquid temperature set point asdetermined by the processing device associated with the subsystem.

2. Description of the Prior Art

Many industrial processing devices and applications require cooling andchilling of the units to remove excess heat generated by the device andallow the device to continue to operate normally. Many different systemsand methods have been proposed to provide and regulate such coolingcapacity, each of which have inherent advantages and disadvantages. Oneexample of the prior art is shown in FIG. 1 as the schematic of atypical water loop configuration of processing control. Duringoperation, most if not all manufacturing and industrial processingdevices release large quantities of heat. In order to cool down thedevice, cold water or another such liquid with a preset and certaintemperature requirement is fed through pipes adjacent to and in contactwith the device to remove the heat being produced by the device andpermit continuing operation of the device. In currently known systems,the water temperature required by different processing machines ismaintained by dedicated chillers (conventional or solid state),generally one for each device. Such a system has higher initial cost,higher energy consumption and very complex control requirements in orderto work correctly, and yet these systems are still prone to failure dueto their complexity and temperamental equipment elements.

Ideally, a system would be devised for cooling such industrialprocessing devices which takes advantage of already existing systemssuch as HVAC systems or the like which are already installed in thefacility. However, at the current time, there is no known method orsystem which provides an interface between the already installed systemand the industrial processing device cooling system contemplated by thepresent invention. Therefore, it is an object of the present inventionto provide an improved industry processing temperature control systemwhich utilizes an HVAC or other such water delivery system alreadyavailable in the facility for cooling of the industrial processingdevices.

Another object is to provide an improved system for controlling thetemperature of industrial processing devices which includes a number ofsubsystems which are associated with the industrial processing devices,each subsystem connected to a central supply system and including avariable-speed pump, control valve and control device which controls thetemperature of the liquid in the subsystem by speeding up, slowing downor shutting off the pump to ensure that the subsystem liquid temperatureremains approximately equal to the designated liquid temperature setpoint as determined by the processing device associated with thesubsystem.

A further object of the present invention is to provide an improvedsystem for controlling the temperature of industrial processing deviceswhich does not use solid-state chillers for each subsystem to improvereliability and reduce repair frequency.

Still another object is to provide an improved system for controllingthe temperature of industrial processing devices which connects toalready existing water chilling systems used for HVAC systems therebysignificantly decreasing the installation and maintenance costsassociated with the system.

Finally, an object of the present invention is to provide an improvedsystem for controlling the temperature of industrial processing deviceswhich is relatively simple and straightforward in design andconstruction and is safe, efficient and effective in use.

SUMMARY OF THE INVENTION

The present invention provides an industry processing temperaturecontrol system including a central liquid supply for providing liquidvia a main liquid circulation system having a main liquid supply loopsection and a main return section, the liquid being provided at anadjustable set temperature and at least one processing devicetemperature control subsystem for generally maintaining the temperatureof liquid being circulated around an industrial processing device at adesignated liquid temperature set point. The processing devicetemperature control subsystem includes a subsystem liquid circulationloop in liquid transfer connection with the main liquid supply loopsection and the main return section of the main liquid circulationmeans, the subsystem liquid circulation loop operative to circulateliquid in a continuous loop partially adjacent the processing device foralternatively reducing or increasing the temperature of the processingdevice via thermal transfer therebetween and a first control valveoperatively interposed between the main liquid supply loop section andthe subsystem liquid circulation loop. A subsystem liquid temperaturesensor is operative to obtain the temperature of liquid flowing throughthe subsystem liquid circulation loop, and a second control valve isoperatively interposed in the subsystem liquid circulation loop afterthe subsystem liquid circulation loop has passed adjacent the processingdevice. A subsystem variable-speed liquid pump is operatively interposedin the subsystem liquid circulation loop after the second control valveand a subsystem control device is operatively connected to the firstcontrol valve, the second control valve and the subsystem variable pumpand is in information transmission connection with the subsystem liquidtemperature sensor. The subsystem control device is operative to readthe current temperature of liquid flowing through the subsystem liquidcirculation loop from the subsystem liquid temperature sensor, comparethe current temperature with the designated liquid temperature setpoint, accelerate the liquid pump if the current temperature is lowerthan the designated liquid temperature set point, decelerate the liquidpump if the current temperature is higher than the designated liquidtemperature set point and stop the liquid pump and shut the secondcontrol valve if the current temperature is approximately equal to thedesignated liquid temperature set point.

The present invention thus provides a substantial improvement over thosesystems and methods found in the prior art which are designed to providecooling and heating water to industrial processing devices and systems.First of all, the proposed system has the advantage of considerablyreducing the initial equipment cost by replacing expensive solid statechillers with commonly available circulation pumps and accessories.Also, the present system guarantees the desired water temperature andwater flow with low energy consumption as it is part of the main watersupply system, hence not requiring its own dedicated system foroperation thereof. Perhaps most importantly from an operationalstandpoint, however, is that the present invention greatly reducesrequired maintenance time and expenses as the components of the systemare tried and true pumps, valves and pipes, thus eliminating solid-statechillers which are notoriously prone to breakdowns and failures. It istherefore seen that the present invention provides a substantialimprovement over those systems and methods found on the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the prior art systems currently usedfor cooling of industrial processing devices;

FIG. 2 is a schematic diagram of the system of the present inventionused for cooling of industrial processing devices;

FIG. 3 is a detailed schematic diagram of one example of the improvedsystem of the present invention; and

FIG. 4 is a flowchart showing the decision-making processes of thecontrol device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

To overcome the disadvantage of the existing system and also satisfy thedifferent temperature requirements of different processing machines, anew system configuration as shown in FIG. 2 is proposed. In the industryprocessing temperature control system 10 of the present invention,conventional or solid state chillers are eliminated. The presentinvention would be connected to a chilled liquid providing system 100which includes a main liquid circulation system 102 having a main liquidsupply loop section 104 and a main return section 106, the liquid being,in the ordinary case, water which is provided at an adjustable settemperature by any appropriate water chilling device of the kind usedwith HVAC systems and the like.

The industry processing temperature control system 10 of the presentinvention includes a plurality of processing device temperature controlsubsystems 12, 14, and 16, each of which are generally identical inbasic format, and thus the following description of processing devicetemperature control subsystem 12 should be understood to apply generallyto any of the other subsystems, with minor operating variations. Theprocessing device temperature control subsystem 12 would preferablyinclude a subsystem liquid circulation loop 20 which is in liquidtransfer connection with the main liquid supply loop section 104, thesubsystem liquid circulation loop 20 operative to circulate the chilledwater in a continuous loop partially adjacent the processing device 80in such a manner that the operating temperature of the processing devicemay be reduced through thermal transfer of excess heat to the liquidcirculating within subsystem liquid circulation loop 20. The preciselocation, size, shape and pipe construction material of the subsystemliquid circulation loop 20 as it threads its way through the processingdevice 80 will be generally dependent on the particular processingdevice 80 with which the present invention is to be used, but should benoted that the chilling systems currently available already includepreferred layouts of water circulation loops through various types ofprocessing devices 80 and therefore adoption of those preferredcirculation loop arrangements for use with the present invention isgenerally contemplated.

Interposed between the connection of the subsystem liquid circulationloop 20 to the main liquid supply loop section 104 is a first controlvalve 22 which, in the preferred embodiment, would be two-way controlvalve which is controlled to maintain water loop differential pressureof the processing machine in the preferred differential pressure range.The first control valve 22 would preferably be a modulating valve whichwould be selected based on the pressure within main liquid circulationsystem 102 and the branch water flow into subsystem liquid circulationloop 20, and the selection will generally follow common control valveselection guidelines.

After passing through the first control valve 22, water flow through thesubsystem liquid circulation loop 20 enters the inner circulation loop24 where the temperature of the water within the inner circulation loop24 prior to encountering the processing device 80 is measured viatemperature sensor 26 which, in the preferred embodiment, may be of anyappropriate design so long as the temperature of the water circulatingwithin inner circulation loop 24 may be accurately determined. The waterwithin inner circulation loop 24 then passes through and around theprocessing device 80 and a pressure sensor 28 is operatively associatedwith inner circulation loop 24 to determine the differential pressurewithin the inner circulation loop 24, as shown in FIGS. 2 and 3. Theinner circulation loop 24 then releases the water passing therethroughinto the main return section 106 so long as the temperature of the wateras measured by the temperature sensor 26 is approximately equal to thedesignated liquid temperature set point usable in connection with theprocessing device 80 to keep the operating temperature of the processingdevice 80 within its preferred operating range.

Should the temperature of the water within inner circulation loop 24 bedetermined to be either higher or lower than the designated temperatureset point, however, the present invention provides a simple,straightforward and economical system by which the temperature withininner circulation loop 24 may be adjusted. Specifically, innercirculation loop 24 further includes an inner circulation loop returnsection 25 which includes second control valve 30 and a circulation pump32 operative such that upon determining that the current watertemperature as measured via temperature sensor 26 is lower than thedesignated liquid temperature set point, the circulation pump 32 isaccelerated to accelerate the flow of water through the innercirculation loop 24 thereby increasing the volume of water flowingthrough the inner circulation loop 24 as controlled by source controlvalve 22 and thus increasing the thermal transfer rate from theprocessing device 80 to the water circulating within inner circulationloop 24. Conversely, if the current water temperature as measured bytemperature sensor 24 is higher than the designated liquid temperatureset point, the circulation pump 32 will be decelerated to decrease theflow of water through inner circulation loop 24, thus decreasing thethermal transfer rate from the processing device 80 thereby maintainingthe operating temperature of the processing device 80 within apredetermined temperature range.

Along with the temperature regulation of the water within the innercirculation loop 24, the differential pressure within the innercirculation loop 24 must also be maintained, and this is done bymeasuring the differential pressure via pressure sensor 28 and if thedifferential pressure is higher than the designated differentialpressure set point, first control valve 22 is gradually closed torestrict water flow through the inner circulation loop 24, and if thedifferential pressure is lower than the differential pressure set point,the first control valve 22 is gradually opened to increase water flowthrough the inner circulation loop 24. In this manner, both thedifferential pressure and temperature of the water within the innercirculation loop 24 of subsystem liquid circulation loop 20 ismaintained within preset values, thus optimizing operation of theprocessing device 80 by maintaining its temperature within a prescribedtemperature range.

All of the above-described functions are monitored and controlled by aprogrammable control device 40 which, in the preferred embodiment, wouldbe a programmable computer system or microchip, depending on thecomplexity of the system, and which is operatively connected to thefirst control valve 22, temperature sensor 26, pressure sensor 28,second control valve 30, and circulation pump 32 in order to provideaccurate real-time control for each of the elements of the subsystemliquid circulation loop 20. The programming of the control device 40would be understood by one skilled in the art of such water circulationsystems, and therefore detailed description of the particular softwareprogramming is deemed unnecessary in this disclosure so long as thedecision-making processes as shown in FIG. 4 and the intendedfunctionality of each of the elements of the inner circulation loop 24are accurately incorporated and controlled by the control device 40. Itshould also be noted that the subsystem liquid circulation loop 20 mayfurther include features such as the gate valve 34 and check valve 36each of which are common pumping and piping system accessories whichwill be installed as needed to ensure proper water flow within thesubsystem liquid circulation loop 20.

It is to be understood that numerous additions, modifications andsubstitutions may be made to the industry processing temperature controlsystem 10 of the present invention which fall within the intended broadscope of the appended claims. For example, the precise needs of eachprocessing device 80 with which the present invention is to be used willbe determined on a case-by-case basis and the subsystem liquidcirculation loop 20 will be modified to accommodate such requirements byutilizing appropriate control valves 22 and 30 or other such pump andpiping system auxiliaries which would be required for proper operationof the subsystem liquid circulation loop 20. Furthermore, the precisenature of the control device 40 is not particularly critical to thepresent invention so long as the control device 40 can perform thenecessary comparisons between current temperature and preferredoperating temperature and current differential pressure and preferredoperating differential pressure necessary for proper operation of theprocessing device temperature control subsystem 12. Also, it should benoted that although the present invention has been described asprimarily for use with industrial processing devices 80, it may be usedin any processing water system which requires accurate temperatureand/or differential pressure control, or even may be used for districtcooling and district heating systems. In such situations, various motorsmay be substituted for the circulation pump 32 and motor associatedtherewith, such as substituting an AC motor with a variable frequencydrive for larger horsepower pumps for the direct current motor currentlyproposed for use with the present invention. Finally, the specificoperating speeds and pressures utilized in connection with the subsystemliquid circulation loop 20 may be modified or changed depending on theprocessing device 80 with which the system is to be used, and suchadjustments and modifications will be understood by those skilled in theart of such cooling systems.

There has therefore been shown and described an industry processingtemperature control system 10 which accomplishes at least all of itsintended objectives.

1. An industry processing temperature control system comprising: acentral liquid supply means for providing liquid via a main liquidcirculation means having a main liquid supply loop section and a mainreturn section, said liquid being provided at an adjustable settemperature; at least one processing device temperature controlsubsystem for generally maintaining the temperature of liquid beingcirculated around an industrial processing device at a designated liquidtemperature set point, said at least one processing device temperaturecontrol subsystem including; a subsystem liquid circulation loop inliquid transfer connection with said main liquid supply loop section andsaid main return section of said main liquid circulation means, saidsubsystem liquid circulation loop operative to circulate liquid in acontinuous loop partially adjacent the industrial processing device foralternatively reducing or increasing the temperature of the industrialprocessing device via thermal transfer therebetween; a first controlvalve operatively interposed between said main liquid supply loopsection and said subsystem liquid circulation loop; subsystem liquidtemperature sensing means operative to obtain the temperature of liquidflowing through said subsystem liquid circulation loop; a second controlvalve operatively interposed in said subsystem liquid circulation loopafter said subsystem liquid circulation loop has passed adjacent theprocessing device and the connection of said subsystem liquidcirculation loop to said main return section of said main liquidcirculation system; a subsystem variable-speed liquid pump operativelyinterposed in said subsystem liquid circulation loop after said secondcontrol valve; subsystem control means operatively connected to saidfirst control valve, said second control valve and said subsystemvariable pump means and in information transmission connection with saidsubsystem liquid temperature sensing means; and said subsystem controlmeans operative to read the current temperature of liquid flowingthrough said subsystem liquid circulation loop from said subsystemliquid temperature sensing means, compare said current temperature withthe designated liquid temperature set point, accelerate said liquid pumpif said current temperature is lower than the designated liquidtemperature set point, decelerate said liquid pump if said currenttemperature is higher than the designated liquid temperature set pointand stop said liquid pump and shut said second control valve if saidcurrent temperature is approximately equal to the designated liquidtemperature set point whereby liquid flows directly through saidsubsystem liquid circulation loop from said main liquid supply loopsection around an industrial processing device and out into said mainreturn section of said main liquid circulation means.
 2. The industryprocessing temperature control system of claim 1 wherein said subsystemliquid circulation loop further comprises a subsystem liquiddifferential pressure sensing means in information transmissionconnection with said subsystem control means and operative to obtain thepressure of liquid flowing through said subsystem liquid circulationloop.
 3. The industry processing temperature control system of claim 2wherein said subsystem control means is further operative to read thecurrent pressure of liquid flowing through said subsystem liquidcirculation loop from said subsystem liquid differential pressuresensing means, compare said current pressure with a designated liquidpressure set point, gradually close said first control valve to decreaseliquid flow therethrough if said current pressure is higher than thedesignated liquid pressure set point and gradually open said firstcontrol valve to increase liquid flow therethrough if said currentpressure is lower than the designated liquid pressure set point.
 4. Theindustry processing temperature control system of claim 1 wherein saidsubsystem control means comprises a programmable computer system.
 5. Theindustry processing temperature control system of claim 1 furthercomprising a gate valve and a check valve mounted within said subsystemliquid circulation loop, said gate valve interposed between said secondcontrol valve and said subsystem variable-speed liquid pump and saidcheck valve interposed between said subsystem variable-speed liquid pumpand the section of said subsystem liquid circulation loop which ispartially adjacent the industrial processing device.
 6. An industryprocessing temperature control system for connection to a central liquidsupply source for providing liquid via a main liquid circulation systemhaving a main liquid supply loop section and a main return section, theliquid being provided at an adjustable set temperature, comprising: atleast one processing device temperature control subsystem for generallymaintaining the temperature of liquid being circulated around anindustrial processing device at a designated liquid temperature setpoint, said at least one processing device temperature control subsystemincluding; a subsystem liquid circulation loop in liquid transferconnection with the central liquid supply source, said subsystem liquidcirculation loop operative to circulate liquid in a continuous looppartially adjacent the industrial processing device for alternativelyreducing or increasing the temperature of the industrial processingdevice via thermal transfer therebetween; a first control valveoperatively interposed between the main liquid supply loop section andsaid subsystem liquid circulation loop; subsystem liquid temperaturesensing means operative to obtain the temperature of liquid flowingthrough said subsystem liquid circulation loop; a second control valveoperatively interposed in said subsystem liquid circulation loop aftersaid subsystem liquid circulation loop has passed adjacent theprocessing device and the connection of said subsystem liquidcirculation loop to the main return section of the main liquidcirculation system; a subsystem variable-speed liquid pump operativelyinterposed in said subsystem liquid circulation loop after said secondcontrol valve; subsystem control means operatively connected to saidfirst control valve, said second control valve and said subsystemvariable pump means and in information transmission connection with saidsubsystem liquid temperature sensing means; and said subsystem controlmeans operative to read the current temperature of liquid flowingthrough said subsystem liquid circulation loop from said subsystemliquid temperature sensing means, compare said current temperature withthe designated liquid temperature set point, accelerate said liquid pumpif said current temperature is lower than the designated liquidtemperature set point, decelerate said liquid pump if said currenttemperature is higher than the designated liquid temperature set pointand stop said liquid pump and shut said second control valve if saidcurrent temperature is approximately equal to the designated liquidtemperature set point whereby liquid flows directly through saidsubsystem liquid circulation loop from the main liquid supply loopsection around an industrial processing device and out into the mainreturn section of the main liquid circulation means.
 7. The industryprocessing temperature control system of claim 6 wherein said subsystemliquid circulation loop further comprises a subsystem liquiddifferential pressure sensing means in information transmissionconnection with said subsystem control means and operative to obtain thepressure of liquid flowing through said subsystem liquid circulationloop.
 8. The industry processing temperature control system of claim 7wherein said subsystem control means is further operative to read thecurrent pressure of liquid flowing through said subsystem liquidcirculation loop from said subsystem liquid differential pressuresensing means, compare said current pressure with a designated liquidpressure set point, gradually close said first control valve to decreaseliquid flow therethrough if said current pressure is higher than thedesignated liquid pressure set point and gradually open said firstcontrol valve to increase liquid flow therethrough if said currentpressure is lower than the designated liquid pressure set point.
 9. Theindustry processing temperature control system of claim 6 wherein saidsubsystem control means comprises a programmable computer system. 10.The industry processing temperature control system of claim 6 furthercomprising a gate valve and a check valve mounted within said subsystemliquid circulation loop, said gate valve interposed between said secondcontrol valve and said subsystem variable-speed liquid pump and saidcheck valve interposed between said subsystem variable-speed liquid pumpand the section of said subsystem liquid circulation loop which ispartially adjacent the industrial processing device.
 11. An industryprocessing temperature control system comprising: a central liquidsupply means for providing liquid via a main liquid circulation meanshaving a main liquid supply loop section and a main return section, saidliquid being provided at an adjustable set temperature; at least oneprocessing device temperature control subsystem for generallymaintaining the temperature of liquid being circulated around anindustrial processing device at a designated liquid temperature setpoint, said at least one processing device temperature control subsystemincluding; a subsystem liquid circulation loop in liquid transferconnection with said main liquid supply loop section and said mainreturn section of said main liquid circulation means, said subsystemliquid circulation loop operative to circulate liquid in a continuousloop partially adjacent the industrial processing device foralternatively reducing or increasing the temperature of the industrialprocessing device via thermal transfer therebetween; a first controlvalve operatively interposed between said main liquid supply loopsection and said subsystem liquid circulation loop; subsystem liquidtemperature sensing means operative to obtain the temperature of liquidflowing through said subsystem liquid circulation loop; subsystem liquiddifferential pressure sensing means in information transmissionconnection with said subsystem control means operative to obtain thepressure of liquid flowing through said subsystem liquid circulationloop; a second control valve operatively interposed in said subsystemliquid circulation loop after said subsystem liquid circulation loop haspassed adjacent the processing device and the connection of saidsubsystem liquid circulation loop to said main return section of saidmain liquid circulation system; a subsystem variable-speed liquid pumpoperatively interposed in said subsystem liquid circulation loop aftersaid second control valve; subsystem control means operatively connectedto said first control valve, said second control valve and saidsubsystem variable pump means and in information transmission connectionwith said subsystem liquid temperature sensing means; said subsystemcontrol means operative to read the current temperature of liquidflowing through said subsystem liquid circulation loop from saidsubsystem liquid temperature sensing means, compare said currenttemperature with the designated liquid temperature set point, acceleratesaid liquid pump if said current temperature is lower than thedesignated liquid temperature set point, decelerate said liquid pump ifsaid current temperature is higher than the designated liquidtemperature set point and stop said liquid pump and shut said secondcontrol valve if said current temperature is approximately equal to thedesignated liquid temperature set point whereby liquid flows directlythrough said subsystem liquid circulation loop from said main liquidsupply loop section around an industrial processing device and out intosaid main return section of said main liquid circulation means; and saidsubsystem control means further operative to read the current pressureof liquid flowing through said subsystem liquid circulation loop fromsaid subsystem liquid differential pressure sensing means, compare saidcurrent pressure with a designated liquid pressure set point, graduallyclose said first control valve to decrease liquid flow therethrough ifsaid current pressure is higher than the designated liquid pressure setpoint and gradually open said first control valve to increase liquidflow therethrough if said current pressure is lower than the designatedliquid pressure set point.